Broadband polarization-independent resonant light absorption using ultrathin plasmonic super absorbers

Abstract

Resonant plasmonic and metamaterial structures allow for control of fundamental optical processes such as absorption, emission and refraction at the nanoscale. Considerable recent research has focused on energy absorption processes, and plasmonic nanostructures have been shown to enhance the performance of photovoltaic and thermophotovoltaic cells. Although reducing metallic losses is a widely sought goal in nanophotonics, the design of nanostructured ' black ' super absorbers from materials comprising only lossless dielectric materials and highly refl ective noble metals represents a new research direction. Here we demonstrate an ultrathin (260 nm) plasmonic super absorber consisting of a metal -insulatormetal stack with a nanostructured top silver fi lm composed of crossed trapezoidal arrays. Our super absorber yields broadband and polarization-independent resonant light absorption over the entire visible spectrum (400 -700 nm) with an average measured absorption of 0.71 and simulated absorption of 0.85. Proposed nanostructured absorbers open a path to realize ultrathin black metamaterials based on resonant absorption.

Compact photonic-crystal superabsorbers from strongly absorbing media

“…We further investigate where is the light getting absorbed while crossing the PC structure. For this purpose, we calculate the ratio of dissipated to incident power within the jth SiC layer, P(j), by applying Poynting's theorem: 18,40 PðjÞ ¼ xe 00 cjE 0 j 2…”

“…2 Many current works go beyond the latter approach with focused efforts around absorption optimization by nano/micro-structuring the absorber and/or its environment, [14][15][16][17] including structures aiming for plasmon-mediated near-field enhancement in the vicinity of the absorber. 4,5,8,9,11,18 Photonic-crystals (PCs) have been researched for absorption control both as back-reflector components [19][20][21] and directly as the absorptive medium. [22][23][24][25][26] The latter cases seem promising schemes for one-step absorption platforms where the lossy photonic crystal could facilitate the incoupling of all impinging light and at the same time would mold the coupled mode in a fashion that enables all light to get absorbed.…”

Midinfrared Surface Plasmons in Carbon Nanotube Plasmonic Metasurface

“…Since SP modes are characterized by the large enhancement of the electromagnetic field, plasmonic metasurfaces are being investigated to improve light harvesting efficiency in solar cells [6][7][8] and to overcome low intrinsic absorption of monolayer graphene [9][10][11][12][13]. In plasmonic structures, the field is primarily localized in the dielectric adjacent to metal, which results in an additional absorption in the vicinity of SP resonance [14,15]. Since metals have extremely large dielectric constants in the visible and IR ranges, the field does not penetrate deeply into the volume of the metal itself, and excitation of SPs on metals patterned with subwavelength holes does not affect absorption much, but rather leads to an extraordinary optical transmission [16,17].…”

Fabrication of multilayer metamaterials by femtosecond laser‐induced forward‐transfer technique

“…However, except for the few successful examples mentioned above, fabricating micro-and nanoplasmonic metamaterial with multilayer fine structures by the LDW technique has not yet been well developed. Therefore, it is highly desired to further extend the LDW technique in fabricating complex plasmonic metamaterial systems and devices [12,16,30].…”